Thread rolling machine and work feeding means therefor



Feb. 2, 1960 c, HANNA 2,923,185

THREAD ROLLING MACHINE AND WORK FEEDING MEANS THEREFOR Filed Aug. 8, 1955 2 Sheets-Sheet 1 INVENTOR EDWARD C. HANNA ATTORNEYS 2,923,185 THREAD ROLLING MACHINE AND WORK FEEDING MEANS THEREFOR Filed Aug. 8, 1955 Feb. 2, 1960 E. c. HANNA 2 Sheets-Sheet 2 INVENTOR EDWARD c. HANNA BY M ATTORNEYS die move downwardly relative to the rolling operation takes place.

THREAD ROLLING MACHINE AND WORK FEEDING MEANS THEREFOR Edward C. Hanna, Waynesboro, Pa., assignor to Landis Machine Company, Waynesboro, Pa., a corporation of Pennsylvania Application August 8, 1955, Serial No. 526,918 3 Claims. (Cl. 80-6) This invention relatesto cold forming machines and particularly to machines employing a pair of rotatable drical in which case the profiles on their opposed peripheral faces are caused to approach .each other to penetrate a work piece by mounting one roll spindle on a slide for lateral reciprocation, while the axis of the other roll is fixed. In another case, the axes of 'both rolls are fixed but one roll is formed with a number of spirally rising or eccentric segments to effect the necessary lateral movement of the rolling profile, while the second roll is cylindrical. The present invention relates particularly to the latter case. Although the rolling of screw threads is referred to exclusively in this description, it is to be understood that various types of v profiles can be formed by such means and that the invention is not limited to the generation of threads.

The working station is established between the opposed die profiles in the plane containing the axes of both rolls, which plane is usually horizontal. The Work blanks, held above one of the dies by a vertical magazine, are conveyed one by one to the working station by a transfer cylinder surrounding said one die and conta ining a number of work-receiving slots. One side of each slot also serves as a work rest for the blank during the rolling operation. The transfer cylinder is locked in position during rolling and is free to rotate with the die it surrounds between rolling operations to carry a finished work piece out of the working station and to present a new blank thereto.

In all known machines of this type the rolling die Specifically, the transfer cylinder carrying the work blank and the associated rolling working station while the periphery of the opposed die moves upwardly.

It has been found in practice that under such conditions I the work piece is usually thrown by centrifugal force into contact with the rolling surface of the opposed die. The

work-carrying slot in the transfer cylinder is necessarily made substantially larger than the diameter of the work blank to permit the work diameter to increase as the Consequently when the descending Work blank meets the rising periphery of the opposed roll the blank is lifted from the bottom or work-rest surface of the slot and is caused to assume an indeterminate and often misaligned position in its slot. Since a correct thread cannot be rolled with the work in suchposition, the machine must be slowed to permit the blank to return to the work-rest surface with conse- 2,Z3,i85 Patented Feb. 2, 1960 quent loss of time and increase in the cost of an individual work piece.

It is, accordingly, the primary purpose and object of the present invention to eliminate this disadvantage by providing a novel mechanism affording a new coaction of the dies and transfer cylinder whereby the advantage of gravity assisted movement of the workpiece to and from the working station are retained while any movement imparted to the descending work piece by the rolling dies will be in a direction to hold it on the work-rest surface.

An exemplary mechanism for accomplishing this basic objective comprises, as described in detail below, a gear train for driving the transfer cylinder intermittently from the spindle of the opposed die. The gear train is so arranged that it eifects the desired relative rotation of the cylinder but permits the axes of the rolling dies to be fixed at various distances from each other for rolling work of various diameters. The area in the vicinity of the Working station is kept clear to permit the'machine to be used, alternatively, for through-feed rolling operations. These and other devices, including a friction drive for the cylinder, insure that the general operation of the machine will in no way be impaired or limited by the addition of the present improvement.

It is also an object of the invention to provide novel apparatus for feeding work blanks in a thread rolling machine by means of a transfer cylinder surrounding one die, wherein the transfer cylinder is rotated in a direction opposite to that of the die it surrounds.

Anotherobject is to provide novel thread rolling apparatus including dies rotating in the same direction and a transfer cylinder surrounding one of the dies and rotating intermittently in the opposite direction.

A further object of the invention is to provide mechanism of the above description including means for intermittently driving the transfer cylinder from the spindle of the opposed rolling die.

Still another object is to provide mechanism as described above wherein the cylinder driving means is a gear train between the transfer cylinder and the opposed die spindle, so disposed and constructed as to avoid interfering with the normal operation of the machine, that is for example, to permit the die axes to be adjusted to various spacings for rolling work of different diameters, to permit the transfer cylinder to be locked during the rolling operation, to allow the machine to be used also for through-feed rolling, etc.

Further objects and advantages of the invention will be apparent from the following description of an embodiment of the invention and from the accompanying drawings, wherein Figure 1 is a horizontal sectional view through the axes of the rolling-die spindles of a thread rolling machine constructed in accordance with the invention;

Figure 2 is a vertical sectional view along line 2-2 of Fig. 1; I

Figure 3 is a vertical sectional view along line 3-3 of Fig. 1 with background detail omitted;

Figure 4 is a vertical sectional View along line 4-4 of Fig. 1 with certain parts omitted; and

Figure 5 is a partial sectional view along line 55 of Fig. 2.

Figures 1 and 2 show the chief structural parts of a typical thread rolling machine comprising a bed 20 having a plane top surface for mounting opposed spindle housings 22 and 24. As described in the above-identified copending applications, the spindle housing 22 is ad justably fixed to the bed at all times while the spindle housing 24- is mounted for reciprocating movement toward and'from the housing 22 with provision for alternatively securing the housing 24 in predetermined position and eliminating the reciprocating movement. In the present instance the housing 24 is fixed and the distance between the housings and between the members mounted therein remains constant.

A die spindle 26 is jour'n'alled for rotation in a roller bearing 23 disposed in a suitable bore in housing '22. The spindle 26 extends forwardly from the bearing 28 and at it's outer 'end is journalled in an outboard bearing (not shown) in the bearing bracket 30 secured by means not shown to a vertical wall 32 of the housing 22. Bearing caps '34 and 35 are provided to enclose the ends of the bracket 30. A similar spindle 36 is journalled for rotation in a bearing 38 mounted in a suitable bore in housing 24. The spindle 36 extends forwardly from the bearing 38 in. precisely parallel relationship to the spindle 26 and'its forward end is j'oumalled in a bearing (not shown) in an outboard bearing bracket 40 secured by any convenient means to a vertical wall 42 of the housing24. Bearing caps 44 and'46 enclose the ends of the bracket 40.

Bearing caps '48 and are secured by screws 52 and 54,"respectively, to the housings 22 and 24, respectively, to retain the'bearingsZd and 38 in proper axial position in their bores. An annular seal 56, disposed between the interior of cap 48 and a shoulder 58 on spindle 26, serves to prevent entry of dust and dirt into bearing'28. An annular sealing member 60 is mounted between'the interior of cap 50 and a shoulder 62 on spindle 36 to protect bearing 38.

Spindlesf26 and 36 are driven by a worm gear mechanism "or other conventional means from a common power"source. Both spindles rotate in the 'samedi'rection' as indicated by the arrows in Fig. 2. p

A pair ofth'read rolling dies 64 and '66 are mounted on spindles 26 and '36,respectively, with their peripheral surfaces directly opposed to each other "and'are driven with the'spindles byke'ys 68 and 70, respectively. As shown in Fig. 3, the die 64 is cylindrical with continuous thread profiles 72 around its circumference while the die 66 has'on'its periphery a plurality, three in this example,

of spirally rising or eccentric thread profiles 74. The degree of eccentricity of these rolling segments 74 is "equal to'double the penetration of the'work piece required' s'o that, in effect, the work piece W (Fig. 3) "is pushed into the thread profile 72 on die 64 by rotation ofthe die'66.

Shallow recesses '76 'are formed between the rolling segments 74 on the circumference of the die, 66 to-permit a finished work piece 'to be discharged from the machine.

The rolling die 64 is surrounded by a work transfer cylinder or cage 78 having a plurality of slots 80 in its periphery for transferring work blanks from a feeding station, usually at the point 82 (Fig. 3) at the top of the cage, to a working station between the rolls as indicated by the'work piece W in Fig. 3. The blanks may be brought to the point 82 by any convenient means such asa magazine or automatic feeder. The cage 78 is locked against rotation during a rolling operation, thatis,while one of the rolling segments 74 is passing the working'stati'on. When a recess 76 arrives at the working station the cage 78 is unlocked and caused 'to rotate in'the clockwise direction as shown in Fig. 3 to remove the finished workpiece and to deliver another blank to the working station. The mechanism for performing these functions will be described below.

A spacer ringtldwhich abuts the forward side of the rolling die 64, a sleeve 86 and another spacer 88, are

retained'on the spindle 26 by a pair of locknuts 90' and 92 screwed onia threaded portion of the spindle and adjustably 'united' with each other by screws 94.' A shoulder '96 'formedon the forward end of sleet/e86 retainsan externally threaded sleeve 98 in axial position against the spacer 84. A pair of rings 1(30 and 102 are threaded onto the sleeve 98 and are united and adjustably spaced relative to each other by screws 164. As shown in Fig. 1, the rings 100 and 102 are provided for the purpose of supporting the ends of work blanks whose portions to be threaded are held by the slots 80' in cage 78. To this end the ring 102 is provided with recesses 106 to support the body of the blank under the head while the ring 100 abuts the head of the blank to retain it in proper axial position. The space between rings 100 and N2 is adjustable to accommodate various sizes of screw heads while by rotating both rings on the threaded sleeve 93, the axial position of the rings relative to the cage can be altered to receive work pieces of various lengths.

A plate 108 is secured by screws 110 to the rear end of sleet e98 and extends radially outwardly to lie closely adjacent the forward end of the cage 78, thus enclosing the forward side of the die 64. 'One or more keys 112 formed integrally with the plate 108 extend into corresponding recesses in the cage 78 to insure unitary rotationof'the plate 193, sleeve 98 and rings 100 and "102 with the cage. The plate 108 is also provided with peripheralrecesses 114 (Fig. 3) corresponding in number and location with the slots 80in the cage 78 to accommodate the -work "pieces.

"axially between a 'flan'ge 'l24'forme'd ontherear end of 'a short-sleevel'26 and a plate 128secured'by screws 130% the forward endof said'sleeve, whichtogether with 'plate 128 is mounted"onthe'spindle'26 between the die 64 andthe shoulder 58. Space is provided be- :twe'en'the :outer diameter ."of f the "sleeve 1% and the innerdiameter of latch ring120 for "the insertion'of bearing nedles 131'to eliminateffriction in'the rela- -tive"rotation' of 'the two parts. Thus fthe sleeve 126, p1ate 128,'spacer 84, sleeve 9.8,an'd spacer88are all 'held-infixed positions with respect to spindle 26'between thenuts9h1 and'92and the shoulder 58.

The latch ring 120 has a pluralityof notches-132(Fig. '2)'for med on its; periphery, these notches corresponding in'number'to theslots in' the cage 78. A bracket 134 'is secured by means not shown to the vertical sidewall 32"of spindle housing 22 and has a'bifurcatedjportion extending toward the spindle 26 to support a pin 138.

A lever having a projection142 at'its lowerend is pivotally mounted on the pin138. When the lever 140 is rocked in the counterclockwise direction the projection 142 is disposed in a position to engageone of the notches 132 in latch ring 120, thereby locking the latter against rotation.

To disengage the latch, the lever'1'40' has'a roller 144 attached thereto by a pin 146 and this roller is located so as to be engaged by a cam 148 (Figs.'1'and'2) secured by a radially directed screw 150 to the periphery ofa cam ring 152. The cam ring 152' is mounted on the circumference of the flange portion 1240f the sleeve 126. Theperiphery of the fiange124'has' an annular groove 154 formed therein to receive the end of'a plugf156 carried 'by thecam ring 152 and abutted by a set screw 158. "By -employing this means of' securing the cam'ring152 to the-sleeve 126, the cam ringmay be adjusted rotatively to insure proper synchronism between the cams 148 and the rolling segments 74 ofthe'die66; the*'num ber-ofcams-and segments being "the same. The-lever .140 may bespringbiasedtoward locking position'or-may be positively. :actuatedfor example: by 'the 'mechanism disclosed in-copending application'Serial No..362,353.

Apair oflock nuts 160 and 162, united :by screws 164, are'mounted on a'forward threadedportion of the spindle 36. A sleeve 166 is disposed on spindle 36;be-

5 is mounted between thedie andthe shou1derf62 thus tween nut 160 and the die 66 anda second sleeve 168 holding the die 66 in correct axial position to oppose the die 64. The sleeve 168 has an integral flange 170 on its rearward end and abutting this flange a ring gear 172 is journalled on sleeve 168. The forward .side of the gear 172 is counterbored to receive a friction ring 174 which is constrained to rotate with the sleeve 168 by means of a radial pin 176. The friction ring 174 is split and of resilient construction so that when the ring is relaxed its outer diameter is greater than the diameter of the counterbore in the gear 172 in which it is received. A ring 178, journalled on sleeve 168 is at tached to the forward side of gear 172 by screws 180, the gear being thus held in position axially between die 66, which abuts the ring 178, and the shoulder 170.

As best shown in Figs. 1, 2 and 4, a ring 182 is journaled upon a forward extension of the bearing cap 50 :and is held thereon by an annular plate 184 secured to the cap 50 by screws 186. The ring 182 has a downward projection in theform of a boss 188 having a bore parallelto the spindle 36 to receive a stub shaft 190 '(Fig. 5). The shaft 190 is provided with a head 192 to retain a small spur gear 194, meshing with the gear 172, in fixed axial position on the shaft and against the forward face of the boss 188. A plate 196 is interposed between the head 192 and the gear 194 and has a rectangular groove 198 in its forward surface to engage the flat surfaces 200 formed on the head 192 to prevent rotation of the shaft 190. A snap ring 202 may be used to hold the parts in assembled relation on the boss 188. A needle bearing 204 is provided between the gear 194 and shaft 190 to insure virtually frictionless rotation of the gear. A hardened washer 206 is embedded in the forward surface of boss 188 to absorb the thrust of the needle bearing 204.

A similar boss 208 is formed as an integral part of the bearing cap 48 and is bored to receive a stub shaft 210. A gear 212, meshing with the gears 194 and 122, is journalled on a needle bearing 214 on shaft 210 and is held against the forward surface of boss 208 by the head 216 on the forward end of the shaft and by a snap ring 218 at the rear end thereof. A hardened washer 220 is embedded in the forward surface of boss 208 to abut the bearing 214. The plate 196 is also interposed be tween the head 216 and the gear 212, thus connecting the two shafts 190 and 210 to maintain a constant fixed distance between their centers. As before, the head 216 of shaft 210 is provided with flats 222 to engage the sides of the groove 198 and prevent shaft 210 from rotating. Grease fittings 224 may be installed in the rear ends of shafts 190 and 210 connecting with passages 226 for lubricating the respective needle bearings 204 and 214.

In describing the operation of the above mechanism it will be assumed that the adjustable spindle housing 24 has been secured in a position to provide the proper distance between the spindle axes. It will be apparent that such adjustment must be changed if it is desired to operate on work pieces of a different diameter. In the position of the mechanism shown in Figure 3 of the drawings a rolling operation is in progress and consequently the cage 78 is stationary, the projection 142 (Fig. 2) being engaged in one of the notches 132 in the latch ring 120. The spindles are rotating in the direction indicated by the arrows in Fig. 2. The die 64 and cam ring 152 with its cams 148 rotate with the spindle 26 and the die 66 and the friction ring 174 rotate with the spindle 36. The latch ring 120 which is engaged by the projection 142, is stationary and holds the cage 78 and ring gear 122.

The rolling operation proceeds until the end of the rolling die segment 74 reaches the working station. At this same time one of the cams 148 (Fig. 2) engages the roller 144 to lift the projection 142 out of the notch 132 to free the latch ring 120. The friction ring 174 causes the gear 172 to rotate at the speed and in the direction of spindle 36. Accordingly the meshing gears 194, 212 and 122 are 'also'rotated to revolve the latch ring 120 and cage 78 in a direction-opposite to that of both rolling dies. The recess 76 having arrived at the work station, the cage 78 carries the finished work piece downwardly and discharges it, simultaneously feeding a new work blank to the working station,

The cam ring 152 continues to rotate, carrying the cam 148 past the roller 144, whereupon the lever 140 rocks back to rest the projection 142 on the circumference of the rotating latch ring 120. In the continued rotation of the latch ring 120 another notch 132 arrives adjacent the projection 142 and the cage. is again locked with the new blank at the working station. Locking the cage 78 of course stops the rotation of the gear train and the friction ring, driven with spindle 36, slips in its counterbore during the subsequent rolling operation.

It will be noted in Fig. 3 for example, that the work blank is moving downwardly as it arrives at the working station .while the opposed die 66 is also moving downwardly. Consequently when the blank makes contact with the .die 66 it is urged against the lower or work-rest surface of the slot 80 and is not lifted therefrom nor permitted to assume a misaligned position.

The shaft 210 is constantly. maintained at the same location since it is journalled 'in the stationary bearing cap 48. The axis of shaft 190, on the other hand, can be adjustably rotated about. the center of, spindle 36 by releasing the screws 186 and rotating the ring 182, the screws being tightened when the shaft 190 is disposed in the correct position. Thus the spindle 36 can be adjusted relative to spindle 26 to accommodate various work diameters without disturbing the meshing relationship of the gears.

The idler gear mechanism for connecting the two spindles is disposed well away from the working station, thus permitting the machine to be used for through-feed rolling operations without removing the gear train. It will also be evident that, if neither through-feed rolling nor lateral adjustment of spindle 36 is desired, the idler gears 194 and 212 may be eliminated and a direct drive between gears 122 and 172 substituted.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being'indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

l. A mechanism for rolling work pieces comprising first and second forming rolls mounted for rotation with first and second spindles, respectively, the axes: of which are disposed in a substantially horizontal plane; means mounting said second spindle for movement toward and away from said first spindle; means for rotating said rolls in the same direction about said axes, the adjacent peripheral portions of said first and second rolls, respectively, moving upwardly and downwardly through said plane, a transfer cage surrounding said first roll and adapted, when rotated by a first gear through a predetermined angular increment, to transfer a Work piece from a word feeding station above said rolls to a work forming station between said rolls; a ring gear frictionally driven by said second spindle; brackets carried by said first and second spindles, said brackets supporting intermediate meshing gears which are also in meshing engagement, respectively, with said ring gear and said first gear whereby said ring gear effectively drives said transfer cage in a direction opposite to the direction of rotation of said rolls; and means for adjustably supporting said brackets to maintain said intermediate gears in mesh in all adjusted positions of said spindles.

2. Acmechanism for rolling work pieces comprising, firstand second forming rolls mounted .for rotation with first and second spindles, respectively, the axes'of which are disposed in a substantially horizontal plane; means for rotating said rolls in the same direction about said axes, the adjacent peripheral portions of said first and second rolls moving, respectively, upwardly and downwardly through said ,plane; -a transfer cage surrounding said first roll and adapted when rotated by a first ,gear to transfer a -W01'k piece from a work feeding station .to a work forming station between said rol-ls; latch means normally operative to .lock said cage against rotation; means for periodically reIeasingsaid latchvmeans; a ring gear frictionally driven by said second spindle; brackets carried by said first and second spindles, said brackets supporting meshing spur gears which 'arealso in meshing engagement, respectively, with said ring gear and said first gear, said ring gear and said spur gears being constructed and arranged to rotate said cage in :a direction opposite to the vdirection ofrotation of said rolls when said latch means is released. l

3. Mechanism for rolling workpieces vcomprising first and second forming rolls mounted for rotation with first and second spindles respectively, the axes of which are disposed in a substantially horizontal plane; means mounting one of said spindles for movement toward and away from the other of said spindles; means "for rotating said rolls in the same direction about said axes, the adjacent peripheral portions of .saidv first and second rolls moving respectively upwardly and downwardly through said plane; a transfer cage "surrounding said 'first roll and having a plurality of workpiece receiving notches adapted,

when said transfer cage is rotated in a directionopposite to the direction .ofsaid rolls, to carry a workpiece from a work feeding station above said rolls to a work forming stationbetween said rolls, the lower sidesof said notches providing a work rest when the notches are disposed atsaid work forming station; latch means normally nopera tive .to lock said \cage against rotation with one of said notches disposed .at said work forming station; means rotatable in timed relation withsaid rollsfor periodically releasing said latch means; a gear frictionally driven with said second spindle, idler gears connecting said gear and said cage -for constantly urging said cage in .a direction opposite to the direction of rotation of .said rolls whereby when .said latch -meansisreleased, said workpiece .moves downwardly toward said work forming station .alongwith said adjacent-peripheral portion of said second 1011 whereby .said workpiece is urgedagainst said work rest surface by said second roll, and support structure for :said gear train for maintaining said gear train in meshing engagement with said; gear and said cage throughout the range ofmovementof.saidsecond spindle. r

' References Cited in the file of this patent UNITED .:STATES PATENTS 1,107,621 Landis Aug. 18, "1-914 2,737,833 Plagemann et al. Mar. 13,1956

FGREIGN PATENTS 495,407 "Belgium May i1'5 '1'950 

